The proposed research is concerned with a comprehensive study of renal diseases, especially although not exclusively in childhood, in order to understand the pathogenesis of immune related glomerulonephritis, the nephrotic syndrome, and other significant renal diseases. These studies will include: a continuing comprehensive study of the immunopathology of renal disease; the role of the alternate complement pathway; a study of the fibrinolytic and kinin systems; and investigation of the mechanisms that control glomerular permeability to macromolecules; a study of the role of the glomerular mesangium; and an evaluation of cellular immune mechanism in renal disease. BIBLIOGRAPHIC REFERENCES: Forsgren, A., McLean, R., Michael, A.F. and Quie, P.G.: Studies of the alternate pathway in chelated serum, J. Lab. Clin. Med., 85:904, 1975; Hoyer, J.R., Resnick, H., Michael, A.F., and Vernier, R.L.: Ontogeny of Tamm-Horsfall urinary glycoprotein, Lab. Invest., 30:757, 1974.